TM Wo. 377 



These corrections were applied to the recorded wind data between the 

 periods of August 196^ and June 1965. Although the method is admittedly 

 crude, since the deterioration of the calibration of the BBELS anemometer 

 probably occurred in a non-linear fashion, this correction was considered 

 to be better than none at all. 



All wind observations made after June 1965 were obtained from the Belfort 

 system mounted on the windward side of the tower (in all cases, the west side); 

 hence, no correction was applied to these data* Wind data associated with the 

 wave meter observations (including corrected data from the BBELS anemometer) 

 are tabulated with the wave data in table IV-3. 



Wave Meter Observations 



During the period 30 March I96J+ through 9 September 1965, sixteen series 

 of experimental measurements of surface wave motions were made from the BBELS 

 using the various wave meters discussed in chapter II. Ten of these series 

 were thoroughly analyzed, providing 12U individual measuremtns. (Most of 

 these are discussed in chapter V.) For convenient reference, table IV-2 lists 

 the various experiments and the instruments used. 



Methods of Making Measurements — It should be emphasized that these exper- 

 iments were of an exploratory nature and were designed to evaluate both the 

 instruments and the methods of using them. As the experiments proceeded, 

 innovations were made in both the mounting and the method of suspension of the 

 ducted meters. 



The original intent, in making wave measurements from the BBELS, was to 

 provide a rigid support for the wave meters. However, a proposal tc fabricate 

 a rigid vertical beam mount, which would be supported by the horizontal cross 

 member pipe located about k meters above the water on the west side of the 

 BBELS (see figure IV-^), w &s considered unsatisfactory in at least four respects: 



1. There is no easy access to the bottom legs for mounting the beam 

 supports. Furthermore, the bottom cross members often become flecked with 



oil dripping from the upper storage tanks, which affords slippery pipe walking. 



2. Provision for lowering and raising the instrument for measurements at 

 various subsurface depths would be overly difficult. 



3. The range of depths would be limited by the length of the vertical beam. 



k. Beam mounting would place the instrument quite close to the diagonal 

 side members and to the main legs, of the tower. 



These anticipated difficulties with a rigid mount made it advisable to 

 try to suspend the wave meter by means of cables from the catwalk of the 

 BBELS (beneath the housing). A pyramidal suspension system, involving the 

 use of counterweights, could be tended from readily accessible points on the 

 upper platform and would require no climbing around on the narrow and slippery 



88 



